xref: /netbsd-src/sys/arch/evbarm/dev/plcom.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: plcom.c,v 1.53 2017/11/07 07:21:13 skrll Exp $	*/
2 
3 /*-
4  * Copyright (c) 2001 ARM Ltd
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The name of the company may not be used to endorse or promote
16  *    products derived from this software without specific prior written
17  *    permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
20  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
21  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
23  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
25  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  * Copyright (c) 1998, 1999, 2012 The NetBSD Foundation, Inc.
32  * All rights reserved.
33  *
34  * This code is derived from software contributed to The NetBSD Foundation
35  * by Charles M. Hannum and Nick Hudson.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  *
46  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
47  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
48  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
49  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
50  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
51  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
52  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
53  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
54  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
55  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
56  * POSSIBILITY OF SUCH DAMAGE.
57  */
58 
59 /*
60  * Copyright (c) 1991 The Regents of the University of California.
61  * All rights reserved.
62  *
63  * Redistribution and use in source and binary forms, with or without
64  * modification, are permitted provided that the following conditions
65  * are met:
66  * 1. Redistributions of source code must retain the above copyright
67  *    notice, this list of conditions and the following disclaimer.
68  * 2. Redistributions in binary form must reproduce the above copyright
69  *    notice, this list of conditions and the following disclaimer in the
70  *    documentation and/or other materials provided with the distribution.
71  * 3. Neither the name of the University nor the names of its contributors
72  *    may be used to endorse or promote products derived from this software
73  *    without specific prior written permission.
74  *
75  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
76  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
77  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
78  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
79  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
80  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
81  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
82  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
83  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
84  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
85  * SUCH DAMAGE.
86  *
87  *	@(#)com.c	7.5 (Berkeley) 5/16/91
88  */
89 
90 /*
91  * COM driver for the Prime Cell PL010 and PL011 UARTs. Both are is similar to
92  * the 16C550, but have a completely different programmer's model.
93  * Derived from the NS16550AF com driver.
94  */
95 
96 #include <sys/cdefs.h>
97 __KERNEL_RCSID(0, "$NetBSD: plcom.c,v 1.53 2017/11/07 07:21:13 skrll Exp $");
98 
99 #include "opt_plcom.h"
100 #include "opt_ddb.h"
101 #include "opt_kgdb.h"
102 #include "opt_lockdebug.h"
103 #include "opt_multiprocessor.h"
104 
105 /*
106  * Override cnmagic(9) macro before including <sys/systm.h>.
107  * We need to know if cn_check_magic triggered debugger, so set a flag.
108  * Callers of cn_check_magic must declare int cn_trapped = 0;
109  * XXX: this is *ugly*!
110  */
111 #define cn_trap()				\
112 	do {					\
113 		console_debugger();		\
114 		cn_trapped = 1;			\
115 	} while (/* CONSTCOND */ 0)
116 
117 #include <sys/param.h>
118 #include <sys/systm.h>
119 #include <sys/ioctl.h>
120 #include <sys/select.h>
121 #include <sys/tty.h>
122 #include <sys/proc.h>
123 #include <sys/conf.h>
124 #include <sys/file.h>
125 #include <sys/uio.h>
126 #include <sys/kernel.h>
127 #include <sys/syslog.h>
128 #include <sys/types.h>
129 #include <sys/device.h>
130 #include <sys/malloc.h>
131 #include <sys/timepps.h>
132 #include <sys/vnode.h>
133 #include <sys/kauth.h>
134 #include <sys/intr.h>
135 #include <sys/bus.h>
136 #ifdef RND_COM
137 #include <sys/rndsource.h>
138 #endif
139 
140 #include <evbarm/dev/plcomreg.h>
141 #include <evbarm/dev/plcomvar.h>
142 
143 #include <dev/cons.h>
144 
145 static void plcom_enable_debugport (struct plcom_softc *);
146 
147 void	plcom_config	(struct plcom_softc *);
148 void	plcom_shutdown	(struct plcom_softc *);
149 int	pl010comspeed	(long, long);
150 int	pl011comspeed	(long, long);
151 static	u_char	cflag2lcr (tcflag_t);
152 int	plcomparam	(struct tty *, struct termios *);
153 void	plcomstart	(struct tty *);
154 int	plcomhwiflow	(struct tty *, int);
155 
156 void	plcom_loadchannelregs (struct plcom_softc *);
157 void	plcom_hwiflow	(struct plcom_softc *);
158 void	plcom_break	(struct plcom_softc *, int);
159 void	plcom_modem	(struct plcom_softc *, int);
160 void	tiocm_to_plcom	(struct plcom_softc *, u_long, int);
161 int	plcom_to_tiocm	(struct plcom_softc *);
162 void	plcom_iflush	(struct plcom_softc *);
163 
164 int	plcom_common_getc (dev_t, struct plcom_instance *);
165 void	plcom_common_putc (dev_t, struct plcom_instance *, int);
166 
167 int	plcominit	(struct plcom_instance *, int, int, tcflag_t);
168 
169 dev_type_open(plcomopen);
170 dev_type_close(plcomclose);
171 dev_type_read(plcomread);
172 dev_type_write(plcomwrite);
173 dev_type_ioctl(plcomioctl);
174 dev_type_stop(plcomstop);
175 dev_type_tty(plcomtty);
176 dev_type_poll(plcompoll);
177 
178 int	plcomcngetc	(dev_t);
179 void	plcomcnputc	(dev_t, int);
180 void	plcomcnpollc	(dev_t, int);
181 
182 #define	integrate	static inline
183 void 	plcomsoft	(void *);
184 integrate void plcom_rxsoft	(struct plcom_softc *, struct tty *);
185 integrate void plcom_txsoft	(struct plcom_softc *, struct tty *);
186 integrate void plcom_stsoft	(struct plcom_softc *, struct tty *);
187 integrate void plcom_schedrx	(struct plcom_softc *);
188 void	plcomdiag		(void *);
189 
190 bool	plcom_intstatus(struct plcom_instance *, u_int *);
191 
192 extern struct cfdriver plcom_cd;
193 
194 const struct cdevsw plcom_cdevsw = {
195 	.d_open = plcomopen,
196 	.d_close = plcomclose,
197 	.d_read = plcomread,
198 	.d_write = plcomwrite,
199 	.d_ioctl = plcomioctl,
200 	.d_stop = plcomstop,
201 	.d_tty = plcomtty,
202 	.d_poll = plcompoll,
203 	.d_mmap = nommap,
204 	.d_kqfilter = ttykqfilter,
205 	.d_discard = nodiscard,
206 	.d_flag = D_TTY
207 };
208 
209 /*
210  * Make this an option variable one can patch.
211  * But be warned:  this must be a power of 2!
212  */
213 u_int plcom_rbuf_size = PLCOM_RING_SIZE;
214 
215 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
216 u_int plcom_rbuf_hiwat = (PLCOM_RING_SIZE * 1) / 4;
217 u_int plcom_rbuf_lowat = (PLCOM_RING_SIZE * 3) / 4;
218 
219 static int	plcomconsunit = -1;
220 static struct plcom_instance plcomcons_info;
221 
222 static int plcomconsattached;
223 static int plcomconsrate;
224 static tcflag_t plcomconscflag;
225 static struct cnm_state plcom_cnm_state;
226 
227 static int ppscap =
228 	PPS_TSFMT_TSPEC |
229 	PPS_CAPTUREASSERT |
230 	PPS_CAPTURECLEAR |
231 #ifdef  PPS_SYNC
232 	PPS_HARDPPSONASSERT | PPS_HARDPPSONCLEAR |
233 #endif	/* PPS_SYNC */
234 	PPS_OFFSETASSERT | PPS_OFFSETCLEAR;
235 
236 #ifdef KGDB
237 #include <sys/kgdb.h>
238 
239 static struct plcom_instance plcomkgdb_info;
240 static int plcom_kgdb_attached;
241 
242 int	plcom_kgdb_getc (void *);
243 void	plcom_kgdb_putc (void *, int);
244 #endif /* KGDB */
245 
246 #define	PLCOMDIALOUT_MASK	TTDIALOUT_MASK
247 
248 #define	PLCOMUNIT(x)	TTUNIT(x)
249 #define	PLCOMDIALOUT(x)	TTDIALOUT(x)
250 
251 #define	PLCOM_ISALIVE(sc)	((sc)->enabled != 0 && \
252 				 device_is_active((sc)->sc_dev))
253 
254 #define	BR	BUS_SPACE_BARRIER_READ
255 #define	BW	BUS_SPACE_BARRIER_WRITE
256 #define PLCOM_BARRIER(pi, f)	\
257     bus_space_barrier((pi)->pi_iot, (pi)->pi_ioh, 0, (pi)->pi_size, (f))
258 
259 static uint8_t
260 pread1(struct plcom_instance *pi, bus_size_t reg)
261 {
262 	if (!ISSET(pi->pi_flags, PLC_FLAG_32BIT_ACCESS))
263 		return bus_space_read_1(pi->pi_iot, pi->pi_ioh, reg);
264 
265 	return bus_space_read_4(pi->pi_iot, pi->pi_ioh, reg & -4) >>
266 	    (8 * (reg & 3));
267 }
268 int nhcr;
269 static void
270 pwrite1(struct plcom_instance *pi, bus_size_t o, uint8_t val)
271 {
272 	if (!ISSET(pi->pi_flags, PLC_FLAG_32BIT_ACCESS)) {
273 		bus_space_write_1(pi->pi_iot, pi->pi_ioh, o, val);
274 	} else {
275 		const size_t shift = 8 * (o & 3);
276 		o &= -4;
277 		uint32_t tmp = bus_space_read_4(pi->pi_iot, pi->pi_ioh, o);
278 		tmp = (val << shift) | (tmp & ~(0xff << shift));
279 		bus_space_write_4(pi->pi_iot, pi->pi_ioh, o, tmp);
280 	}
281 }
282 
283 static void
284 pwritem1(struct plcom_instance *pi, bus_size_t o, const uint8_t *datap,
285     bus_size_t count)
286 {
287 	if (!ISSET(pi->pi_flags, PLC_FLAG_32BIT_ACCESS)) {
288 		bus_space_write_multi_1(pi->pi_iot, pi->pi_ioh, o, datap, count);
289 	} else {
290 		KASSERT((o & 3) == 0);
291 		while (count--) {
292 			bus_space_write_4(pi->pi_iot, pi->pi_ioh, o, *datap++);
293 		};
294 	}
295 }
296 
297 #define	PREAD1(pi, reg)		pread1(pi, reg)
298 #define	PREAD4(pi, reg)		\
299 	(bus_space_read_4((pi)->pi_iot, (pi)->pi_ioh, (reg)))
300 
301 #define	PWRITE1(pi, reg, val)	pwrite1(pi, reg, val)
302 #define	PWRITEM1(pi, reg, d, c)	pwritem1(pi, reg, d, c)
303 #define	PWRITE4(pi, reg, val)	\
304 	(bus_space_write_4((pi)->pi_iot, (pi)->pi_ioh, (reg), (val)))
305 
306 int
307 pl010comspeed(long speed, long frequency)
308 {
309 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
310 
311 	int x, err;
312 
313 #if 0
314 	if (speed == 0)
315 		return 0;
316 #endif
317 	if (speed <= 0)
318 		return -1;
319 	x = divrnd(frequency / 16, speed);
320 	if (x <= 0)
321 		return -1;
322 	err = divrnd(((quad_t)frequency) * 1000 / 16, speed * x) - 1000;
323 	if (err < 0)
324 		err = -err;
325 	if (err > PLCOM_TOLERANCE)
326 		return -1;
327 	return x;
328 
329 #undef	divrnd
330 }
331 
332 int
333 pl011comspeed(long speed, long frequency)
334 {
335 	int denom = 16 * speed;
336 	int div = frequency / denom;
337 	int rem = frequency % denom;
338 
339 	int ibrd = div << 6;
340 	int fbrd = (((8 * rem) / speed) + 1) / 2;
341 
342 	/* Tolerance? */
343 	return ibrd | fbrd;
344 }
345 
346 #ifdef PLCOM_DEBUG
347 int	plcom_debug = 0;
348 
349 void plcomstatus (struct plcom_softc *, const char *);
350 void
351 plcomstatus(struct plcom_softc *sc, const char *str)
352 {
353 	struct tty *tp = sc->sc_tty;
354 
355 	printf("%s: %s %sclocal  %sdcd %sts_carr_on %sdtr %stx_stopped\n",
356 	    device_xname(sc->sc_dev), str,
357 	    ISSET(tp->t_cflag, CLOCAL) ? "+" : "-",
358 	    ISSET(sc->sc_msr, PL01X_MSR_DCD) ? "+" : "-",
359 	    ISSET(tp->t_state, TS_CARR_ON) ? "+" : "-",
360 	    ISSET(sc->sc_mcr, PL01X_MCR_DTR) ? "+" : "-",
361 	    sc->sc_tx_stopped ? "+" : "-");
362 
363 	printf("%s: %s %scrtscts %scts %sts_ttstop  %srts %xrx_flags\n",
364 	    device_xname(sc->sc_dev), str,
365 	    ISSET(tp->t_cflag, CRTSCTS) ? "+" : "-",
366 	    ISSET(sc->sc_msr, PL01X_MSR_CTS) ? "+" : "-",
367 	    ISSET(tp->t_state, TS_TTSTOP) ? "+" : "-",
368 	    ISSET(sc->sc_mcr, PL01X_MCR_RTS) ? "+" : "-",
369 	    sc->sc_rx_flags);
370 }
371 #endif
372 
373 #if 0
374 int
375 plcomprobe1(bus_space_tag_t iot, bus_space_handle_t ioh)
376 {
377 	int data;
378 
379 	/* Disable the UART.  */
380 	bus_space_write_1(iot, ioh, plcom_cr, 0);
381 	/* Make sure the FIFO is off.  */
382 	bus_space_write_1(iot, ioh, plcom_lcr, PL01X_LCR_8BITS);
383 	/* Disable interrupts.  */
384 	bus_space_write_1(iot, ioh, plcom_iir, 0);
385 
386 	/* Make sure we swallow anything in the receiving register.  */
387 	data = bus_space_read_1(iot, ioh, plcom_dr);
388 
389 	if (bus_space_read_1(iot, ioh, plcom_lcr) != PL01X_LCR_8BITS)
390 		return 0;
391 
392 	data = bus_space_read_1(iot, ioh, plcom_fr) & (PL01X_FR_RXFF | PL01X_FR_RXFE);
393 
394 	if (data != PL01X_FR_RXFE)
395 		return 0;
396 
397 	return 1;
398 }
399 #endif
400 
401 /*
402  * No locking in this routine; it is only called during attach,
403  * or with the port already locked.
404  */
405 static void
406 plcom_enable_debugport(struct plcom_softc *sc)
407 {
408 	struct plcom_instance *pi = &sc->sc_pi;
409 
410 	sc->sc_cr = PL01X_CR_UARTEN;
411 	SET(sc->sc_mcr, PL01X_MCR_DTR | PL01X_MCR_RTS);
412 
413 	/* Turn on line break interrupt, set carrier. */
414 	switch (pi->pi_type) {
415 	case PLCOM_TYPE_PL010:
416 		SET(sc->sc_cr, PL010_CR_RIE | PL010_CR_RTIE);
417 		PWRITE1(pi, PL010COM_CR, sc->sc_cr);
418 		if (sc->sc_set_mcr) {
419 			/* XXX device_unit() abuse */
420 			sc->sc_set_mcr(sc->sc_set_mcr_arg,
421 			    device_unit(sc->sc_dev), sc->sc_mcr);
422 		}
423 		break;
424 	case PLCOM_TYPE_PL011:
425 		sc->sc_imsc = PL011_INT_RX | PL011_INT_RT;
426 		SET(sc->sc_cr, PL011_CR_RXE | PL011_CR_TXE);
427 		SET(sc->sc_cr, PL011_MCR(sc->sc_mcr));
428 		PWRITE4(pi, PL011COM_CR, sc->sc_cr);
429 		PWRITE4(pi, PL011COM_IMSC, sc->sc_imsc);
430 		break;
431 	}
432 
433 }
434 
435 void
436 plcom_attach_subr(struct plcom_softc *sc)
437 {
438 	struct plcom_instance *pi = &sc->sc_pi;
439 	struct tty *tp;
440 
441 	aprint_naive("\n");
442 
443 	callout_init(&sc->sc_diag_callout, 0);
444 	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_HIGH);
445 
446 	switch (pi->pi_type) {
447 	case PLCOM_TYPE_PL010:
448 	case PLCOM_TYPE_PL011:
449 		break;
450 	default:
451 		aprint_error_dev(sc->sc_dev,
452 		    "Unknown plcom type: %d\n", pi->pi_type);
453 		return;
454 	}
455 
456 	/* Disable interrupts before configuring the device. */
457 	sc->sc_cr = 0;
458 	sc->sc_imsc = 0;
459 
460 	if (bus_space_is_equal(pi->pi_iot, plcomcons_info.pi_iot) &&
461 	    pi->pi_iobase == plcomcons_info.pi_iobase) {
462 		plcomconsattached = 1;
463 
464 		/* Make sure the console is always "hardwired". */
465 		delay(1000);			/* wait for output to finish */
466 		SET(sc->sc_hwflags, PLCOM_HW_CONSOLE);
467 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
468 		/*
469 		 * Must re-enable the console immediately, or we will
470 		 * hang when trying to print.
471 		 */
472 		sc->sc_cr = PL01X_CR_UARTEN;
473 		if (pi->pi_type == PLCOM_TYPE_PL011)
474 			SET(sc->sc_cr, PL011_CR_RXE | PL011_CR_TXE);
475 	}
476 
477 	switch (pi->pi_type) {
478 	case PLCOM_TYPE_PL010:
479 		PWRITE1(pi, PL010COM_CR, sc->sc_cr);
480 		break;
481 
482 	case PLCOM_TYPE_PL011:
483 		PWRITE4(pi, PL011COM_CR, sc->sc_cr);
484 		PWRITE4(pi, PL011COM_IMSC, sc->sc_imsc);
485 		break;
486 	}
487 
488 	if (sc->sc_fifolen == 0) {
489 		switch (pi->pi_type) {
490 		case PLCOM_TYPE_PL010:
491 			/*
492 			 * The PL010 has a 16-byte fifo, but the tx interrupt
493 			 * triggers when there is space for 8 more bytes.
494 			*/
495 			sc->sc_fifolen = 8;
496 			break;
497 		case PLCOM_TYPE_PL011:
498 			/* Some revisions have a 32 byte TX FIFO */
499 			sc->sc_fifolen = 16;
500 			break;
501 		}
502 	}
503 	aprint_normal("\n");
504 
505 	if (ISSET(sc->sc_hwflags, PLCOM_HW_TXFIFO_DISABLE)) {
506 		sc->sc_fifolen = 1;
507 		aprint_normal_dev(sc->sc_dev, "txfifo disabled\n");
508 	}
509 
510 	if (sc->sc_fifolen > 1)
511 		SET(sc->sc_hwflags, PLCOM_HW_FIFO);
512 
513 	tp = tty_alloc();
514 	tp->t_oproc = plcomstart;
515 	tp->t_param = plcomparam;
516 	tp->t_hwiflow = plcomhwiflow;
517 
518 	sc->sc_tty = tp;
519 	sc->sc_rbuf = malloc(plcom_rbuf_size << 1, M_DEVBUF, M_NOWAIT);
520 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
521 	sc->sc_rbavail = plcom_rbuf_size;
522 	if (sc->sc_rbuf == NULL) {
523 		aprint_error_dev(sc->sc_dev,
524 		    "unable to allocate ring buffer\n");
525 		return;
526 	}
527 	sc->sc_ebuf = sc->sc_rbuf + (plcom_rbuf_size << 1);
528 
529 	tty_attach(tp);
530 
531 	if (ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE)) {
532 		int maj;
533 
534 		/* locate the major number */
535 		maj = cdevsw_lookup_major(&plcom_cdevsw);
536 
537 		tp->t_dev = cn_tab->cn_dev = makedev(maj, device_unit(sc->sc_dev));
538 
539 		aprint_normal_dev(sc->sc_dev, "console\n");
540 	}
541 
542 #ifdef KGDB
543 	/*
544 	 * Allow kgdb to "take over" this port.  If this is
545 	 * the kgdb device, it has exclusive use.
546 	 */
547 	if (bus_space_is_equal(pi->pi_iot, plcomkgdb_info.pi_iot) &&
548 	    pi->pi_iobase == plcomkgdb_info.pi_iobase) {
549 		if (!ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE)) {
550 			plcom_kgdb_attached = 1;
551 
552 			SET(sc->sc_hwflags, PLCOM_HW_KGDB);
553 		}
554 		aprint_normal_dev(sc->sc_dev, "kgdb\n");
555 	}
556 #endif
557 
558 	sc->sc_si = softint_establish(SOFTINT_SERIAL, plcomsoft, sc);
559 
560 #ifdef RND_COM
561 	rnd_attach_source(&sc->rnd_source, device_xname(sc->sc_dev),
562 	    RND_TYPE_TTY, RND_FLAG_DEFAULT);
563 #endif
564 
565 	/*
566 	 * if there are no enable/disable functions, assume the device
567 	 * is always enabled
568 	 */
569 	if (!sc->enable)
570 		sc->enabled = 1;
571 
572 	plcom_config(sc);
573 
574 	SET(sc->sc_hwflags, PLCOM_HW_DEV_OK);
575 }
576 
577 void
578 plcom_config(struct plcom_softc *sc)
579 {
580 	struct plcom_instance *pi = &sc->sc_pi;
581 
582 	/* Disable interrupts before configuring the device. */
583 	sc->sc_cr = 0;
584 	sc->sc_imsc = 0;
585 	switch (pi->pi_type) {
586 	case PLCOM_TYPE_PL010:
587 		PWRITE1(pi, PL010COM_CR, sc->sc_cr);
588 		break;
589 
590 	case PLCOM_TYPE_PL011:
591 		PWRITE4(pi, PL011COM_CR, sc->sc_cr);
592 		PWRITE4(pi, PL011COM_IMSC, sc->sc_imsc);
593 		break;
594 	}
595 
596 	if (ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE|PLCOM_HW_KGDB))
597 		plcom_enable_debugport(sc);
598 }
599 
600 int
601 plcom_detach(device_t self, int flags)
602 {
603 	struct plcom_softc *sc = device_private(self);
604 	int maj, mn;
605 
606 	if (sc->sc_hwflags & (PLCOM_HW_CONSOLE|PLCOM_HW_KGDB))
607 		return EBUSY;
608 
609 	if (sc->disable != NULL && sc->enabled != 0) {
610 		(*sc->disable)(sc);
611 		sc->enabled = 0;
612 	}
613 
614 	/* locate the major number */
615 	maj = cdevsw_lookup_major(&plcom_cdevsw);
616 
617 	/* Nuke the vnodes for any open instances. */
618 	mn = device_unit(self);
619 	vdevgone(maj, mn, mn, VCHR);
620 
621 	mn |= PLCOMDIALOUT_MASK;
622 	vdevgone(maj, mn, mn, VCHR);
623 
624 	if (sc->sc_rbuf == NULL) {
625 		/*
626 		 * Ring buffer allocation failed in the plcom_attach_subr,
627 		 * only the tty is allocated, and nothing else.
628 		 */
629 		tty_free(sc->sc_tty);
630 		return 0;
631 	}
632 
633 	/* Free the receive buffer. */
634 	free(sc->sc_rbuf, M_DEVBUF);
635 
636 	/* Detach and free the tty. */
637 	tty_detach(sc->sc_tty);
638 	tty_free(sc->sc_tty);
639 
640 	/* Unhook the soft interrupt handler. */
641 	softint_disestablish(sc->sc_si);
642 
643 #ifdef RND_COM
644 	/* Unhook the entropy source. */
645 	rnd_detach_source(&sc->rnd_source);
646 #endif
647 	callout_destroy(&sc->sc_diag_callout);
648 
649 	/* Destroy the lock. */
650 	mutex_destroy(&sc->sc_lock);
651 
652 	return 0;
653 }
654 
655 int
656 plcom_activate(device_t self, enum devact act)
657 {
658 	struct plcom_softc *sc = device_private(self);
659 
660 	switch (act) {
661 	case DVACT_DEACTIVATE:
662 		sc->enabled = 0;
663 		return 0;
664 	default:
665 		return EOPNOTSUPP;
666 	}
667 }
668 
669 void
670 plcom_shutdown(struct plcom_softc *sc)
671 {
672 	struct plcom_instance *pi = &sc->sc_pi;
673 	struct tty *tp = sc->sc_tty;
674 	mutex_spin_enter(&sc->sc_lock);
675 
676 	/* If we were asserting flow control, then deassert it. */
677 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
678 	plcom_hwiflow(sc);
679 
680 	/* Clear any break condition set with TIOCSBRK. */
681 	plcom_break(sc, 0);
682 
683 	/* Turn off PPS capture on last close. */
684 	mutex_spin_enter(&timecounter_lock);
685 	sc->sc_ppsmask = 0;
686 	sc->ppsparam.mode = 0;
687 	mutex_spin_exit(&timecounter_lock);
688 
689 	/*
690 	 * Hang up if necessary.  Wait a bit, so the other side has time to
691 	 * notice even if we immediately open the port again.
692 	 * Avoid tsleeping above splhigh().
693 	 */
694 	if (ISSET(tp->t_cflag, HUPCL)) {
695 		plcom_modem(sc, 0);
696 		mutex_spin_exit(&sc->sc_lock);
697 		/* XXX will only timeout */
698 		(void) kpause(ttclos, false, hz, NULL);
699 		mutex_spin_enter(&sc->sc_lock);
700 	}
701 
702 	sc->sc_cr = 0;
703 	sc->sc_imsc = 0;
704 	/* Turn off interrupts. */
705 	if (ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE)) {
706 		/* interrupt on break */
707 
708 		sc->sc_cr = PL01X_CR_UARTEN;
709 		sc->sc_imsc = 0;
710 		switch (pi->pi_type) {
711 		case PLCOM_TYPE_PL010:
712 			SET(sc->sc_cr, PL010_CR_RIE | PL010_CR_RTIE);
713 			break;
714 		case PLCOM_TYPE_PL011:
715 			SET(sc->sc_cr, PL011_CR_RXE);
716 			SET(sc->sc_imsc, PL011_INT_RT | PL011_INT_RX);
717 			break;
718 		}
719 	}
720 	switch (pi->pi_type) {
721 	case PLCOM_TYPE_PL010:
722 		SET(sc->sc_cr, PL010_CR_RIE | PL010_CR_RTIE);
723 		PWRITE1(pi, PL010COM_CR, sc->sc_cr);
724 		break;
725 	case PLCOM_TYPE_PL011:
726 		SET(sc->sc_cr, PL011_CR_RXE | PL011_CR_TXE);
727 		SET(sc->sc_imsc, PL011_INT_RT | PL011_INT_RX);
728 		PWRITE4(pi, PL011COM_CR, sc->sc_cr);
729 		PWRITE4(pi, PL011COM_IMSC, sc->sc_imsc);
730 		break;
731 	}
732 
733 	mutex_spin_exit(&sc->sc_lock);
734 	if (sc->disable) {
735 #ifdef DIAGNOSTIC
736 		if (!sc->enabled)
737 			panic("plcom_shutdown: not enabled?");
738 #endif
739 		(*sc->disable)(sc);
740 		sc->enabled = 0;
741 	}
742 }
743 
744 int
745 plcomopen(dev_t dev, int flag, int mode, struct lwp *l)
746 {
747 	struct plcom_softc *sc;
748 	struct plcom_instance *pi;
749 	struct tty *tp;
750 	int s;
751 	int error;
752 
753 	sc = device_lookup_private(&plcom_cd, PLCOMUNIT(dev));
754 	if (sc == NULL || !ISSET(sc->sc_hwflags, PLCOM_HW_DEV_OK) ||
755 		sc->sc_rbuf == NULL)
756 		return ENXIO;
757 
758 	if (!device_is_active(sc->sc_dev))
759 		return ENXIO;
760 
761 	pi = &sc->sc_pi;
762 
763 #ifdef KGDB
764 	/*
765 	 * If this is the kgdb port, no other use is permitted.
766 	 */
767 	if (ISSET(sc->sc_hwflags, PLCOM_HW_KGDB))
768 		return EBUSY;
769 #endif
770 
771 	tp = sc->sc_tty;
772 
773 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
774 		return (EBUSY);
775 
776 	s = spltty();
777 
778 	/*
779 	 * Do the following iff this is a first open.
780 	 */
781 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
782 		struct termios t;
783 
784 		tp->t_dev = dev;
785 
786 		if (sc->enable) {
787 			if ((*sc->enable)(sc)) {
788 				splx(s);
789 				aprint_error_dev(sc->sc_dev,
790 				    "device enable failed\n");
791 				return EIO;
792 			}
793 			mutex_spin_enter(&sc->sc_lock);
794 			sc->enabled = 1;
795 			plcom_config(sc);
796 		} else {
797 			mutex_spin_enter(&sc->sc_lock);
798 		}
799 
800 		/* Turn on interrupts. */
801 		/* IER_ERXRDY | IER_ERLS | IER_EMSC;  */
802 		/* Fetch the current modem control status, needed later. */
803 		sc->sc_cr = PL01X_CR_UARTEN;
804 		switch (pi->pi_type) {
805 		case PLCOM_TYPE_PL010:
806 			SET(sc->sc_cr,
807 			    PL010_CR_RIE | PL010_CR_RTIE | PL010_CR_MSIE);
808 			PWRITE1(pi, PL010COM_CR, sc->sc_cr);
809 			sc->sc_msr = PREAD1(pi, PL01XCOM_FR);
810 			break;
811 		case PLCOM_TYPE_PL011:
812 			SET(sc->sc_cr, PL011_CR_RXE | PL011_CR_TXE);
813 			SET(sc->sc_imsc, PL011_INT_RT | PL011_INT_RX |
814 			    PL011_INT_MSMASK);
815 			PWRITE4(pi, PL011COM_IMSC, sc->sc_imsc);
816 			sc->sc_msr = PREAD4(pi, PL01XCOM_FR);
817 			break;
818 		}
819 
820 		/* Clear PPS capture state on first open. */
821 
822 		mutex_spin_enter(&timecounter_lock);
823 		sc->sc_ppsmask = 0;
824 		sc->ppsparam.mode = 0;
825 		mutex_spin_exit(&timecounter_lock);
826 
827 		mutex_spin_exit(&sc->sc_lock);
828 
829 		/*
830 		 * Initialize the termios status to the defaults.  Add in the
831 		 * sticky bits from TIOCSFLAGS.
832 		 */
833 		if (ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE)) {
834 			t.c_ospeed = plcomconsrate;
835 			t.c_cflag = plcomconscflag;
836 		} else {
837 			t.c_ospeed = TTYDEF_SPEED;
838 			t.c_cflag = TTYDEF_CFLAG;
839 		}
840 		t.c_ispeed = t.c_ospeed;
841 
842 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
843 			SET(t.c_cflag, CLOCAL);
844 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
845 			SET(t.c_cflag, CRTSCTS);
846 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
847 			SET(t.c_cflag, MDMBUF);
848 		/* Make sure plcomparam() will do something. */
849 		tp->t_ospeed = 0;
850 		(void) plcomparam(tp, &t);
851 		tp->t_iflag = TTYDEF_IFLAG;
852 		tp->t_oflag = TTYDEF_OFLAG;
853 		tp->t_lflag = TTYDEF_LFLAG;
854 		ttychars(tp);
855 		ttsetwater(tp);
856 
857 		mutex_spin_enter(&sc->sc_lock);
858 
859 		/*
860 		 * Turn on DTR.  We must always do this, even if carrier is not
861 		 * present, because otherwise we'd have to use TIOCSDTR
862 		 * immediately after setting CLOCAL, which applications do not
863 		 * expect.  We always assert DTR while the device is open
864 		 * unless explicitly requested to deassert it.
865 		 */
866 		plcom_modem(sc, 1);
867 
868 		/* Clear the input ring, and unblock. */
869 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
870 		sc->sc_rbavail = plcom_rbuf_size;
871 		plcom_iflush(sc);
872 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
873 		plcom_hwiflow(sc);
874 
875 #ifdef PLCOM_DEBUG
876 		if (plcom_debug)
877 			plcomstatus(sc, "plcomopen  ");
878 #endif
879 
880 		mutex_spin_exit(&sc->sc_lock);
881 	}
882 
883 	splx(s);
884 
885 	error = ttyopen(tp, PLCOMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
886 	if (error)
887 		goto bad;
888 
889 	error = (*tp->t_linesw->l_open)(dev, tp);
890 	if (error)
891 		goto bad;
892 
893 	return 0;
894 
895 bad:
896 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
897 		/*
898 		 * We failed to open the device, and nobody else had it opened.
899 		 * Clean up the state as appropriate.
900 		 */
901 		plcom_shutdown(sc);
902 	}
903 
904 	return error;
905 }
906 
907 int
908 plcomclose(dev_t dev, int flag, int mode, struct lwp *l)
909 {
910 	struct plcom_softc *sc =
911 		device_lookup_private(&plcom_cd, PLCOMUNIT(dev));
912 	struct tty *tp = sc->sc_tty;
913 
914 	/* XXX This is for cons.c. */
915 	if (!ISSET(tp->t_state, TS_ISOPEN))
916 		return 0;
917 
918 	(*tp->t_linesw->l_close)(tp, flag);
919 	ttyclose(tp);
920 
921 	if (PLCOM_ISALIVE(sc) == 0)
922 		return 0;
923 
924 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
925 		/*
926 		 * Although we got a last close, the device may still be in
927 		 * use; e.g. if this was the dialout node, and there are still
928 		 * processes waiting for carrier on the non-dialout node.
929 		 */
930 		plcom_shutdown(sc);
931 	}
932 
933 	return 0;
934 }
935 
936 int
937 plcomread(dev_t dev, struct uio *uio, int flag)
938 {
939 	struct plcom_softc *sc =
940 		device_lookup_private(&plcom_cd, PLCOMUNIT(dev));
941 	struct tty *tp = sc->sc_tty;
942 
943 	if (PLCOM_ISALIVE(sc) == 0)
944 		return EIO;
945 
946 	return (*tp->t_linesw->l_read)(tp, uio, flag);
947 }
948 
949 int
950 plcomwrite(dev_t dev, struct uio *uio, int flag)
951 {
952 	struct plcom_softc *sc =
953 		device_lookup_private(&plcom_cd, PLCOMUNIT(dev));
954 	struct tty *tp = sc->sc_tty;
955 
956 	if (PLCOM_ISALIVE(sc) == 0)
957 		return EIO;
958 
959 	return (*tp->t_linesw->l_write)(tp, uio, flag);
960 }
961 
962 int
963 plcompoll(dev_t dev, int events, struct lwp *l)
964 {
965 	struct plcom_softc *sc =
966 		device_lookup_private(&plcom_cd, PLCOMUNIT(dev));
967 	struct tty *tp = sc->sc_tty;
968 
969 	if (PLCOM_ISALIVE(sc) == 0)
970 		return EIO;
971 
972 	return (*tp->t_linesw->l_poll)(tp, events, l);
973 }
974 
975 struct tty *
976 plcomtty(dev_t dev)
977 {
978 	struct plcom_softc *sc =
979 		device_lookup_private(&plcom_cd, PLCOMUNIT(dev));
980 	struct tty *tp = sc->sc_tty;
981 
982 	return tp;
983 }
984 
985 int
986 plcomioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
987 {
988 	struct plcom_softc *sc =
989 		device_lookup_private(&plcom_cd, PLCOMUNIT(dev));
990 	struct tty *tp;
991 	int error;
992 
993 	if (sc == NULL)
994 		return ENXIO;
995 	if (PLCOM_ISALIVE(sc) == 0)
996 		return EIO;
997 
998 	tp = sc->sc_tty;
999 
1000 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
1001 	if (error != EPASSTHROUGH)
1002 		return error;
1003 
1004 	error = ttioctl(tp, cmd, data, flag, l);
1005 	if (error != EPASSTHROUGH)
1006 		return error;
1007 
1008 	error = 0;
1009 	switch (cmd) {
1010 	case TIOCSFLAGS:
1011 		error = kauth_authorize_device_tty(l->l_cred,
1012 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
1013 		break;
1014 	default:
1015 		/* nothing */
1016 		break;
1017 	}
1018 	if (error) {
1019 		return error;
1020 	}
1021 
1022 	mutex_spin_enter(&sc->sc_lock);
1023 	switch (cmd) {
1024 	case TIOCSBRK:
1025 		plcom_break(sc, 1);
1026 		break;
1027 
1028 	case TIOCCBRK:
1029 		plcom_break(sc, 0);
1030 		break;
1031 
1032 	case TIOCSDTR:
1033 		plcom_modem(sc, 1);
1034 		break;
1035 
1036 	case TIOCCDTR:
1037 		plcom_modem(sc, 0);
1038 		break;
1039 
1040 	case TIOCGFLAGS:
1041 		*(int *)data = sc->sc_swflags;
1042 		break;
1043 
1044 	case TIOCSFLAGS:
1045 		sc->sc_swflags = *(int *)data;
1046 		break;
1047 
1048 	case TIOCMSET:
1049 	case TIOCMBIS:
1050 	case TIOCMBIC:
1051 		tiocm_to_plcom(sc, cmd, *(int *)data);
1052 		break;
1053 
1054 	case TIOCMGET:
1055 		*(int *)data = plcom_to_tiocm(sc);
1056 		break;
1057 
1058 	case PPS_IOC_CREATE:
1059 		break;
1060 
1061 	case PPS_IOC_DESTROY:
1062 		break;
1063 
1064 	case PPS_IOC_GETPARAMS: {
1065 		pps_params_t *pp;
1066 		pp = (pps_params_t *)data;
1067 		mutex_spin_enter(&timecounter_lock);
1068 		*pp = sc->ppsparam;
1069 		mutex_spin_exit(&timecounter_lock);
1070 		break;
1071 	}
1072 
1073 	case PPS_IOC_SETPARAMS: {
1074 	  	pps_params_t *pp;
1075 		int mode;
1076 		pp = (pps_params_t *)data;
1077 		mutex_spin_enter(&timecounter_lock);
1078 		if (pp->mode & ~ppscap) {
1079 			error = EINVAL;
1080 			mutex_spin_exit(&timecounter_lock);
1081 			break;
1082 		}
1083 		sc->ppsparam = *pp;
1084 	 	/*
1085 		 * Compute msr masks from user-specified timestamp state.
1086 		 */
1087 		mode = sc->ppsparam.mode;
1088 #ifdef	PPS_SYNC
1089 		if (mode & PPS_HARDPPSONASSERT) {
1090 			mode |= PPS_CAPTUREASSERT;
1091 			/* XXX revoke any previous HARDPPS source */
1092 		}
1093 		if (mode & PPS_HARDPPSONCLEAR) {
1094 			mode |= PPS_CAPTURECLEAR;
1095 			/* XXX revoke any previous HARDPPS source */
1096 		}
1097 #endif	/* PPS_SYNC */
1098 		switch (mode & PPS_CAPTUREBOTH) {
1099 		case 0:
1100 			sc->sc_ppsmask = 0;
1101 			break;
1102 
1103 		case PPS_CAPTUREASSERT:
1104 			sc->sc_ppsmask = PL01X_MSR_DCD;
1105 			sc->sc_ppsassert = PL01X_MSR_DCD;
1106 			sc->sc_ppsclear = -1;
1107 			break;
1108 
1109 		case PPS_CAPTURECLEAR:
1110 			sc->sc_ppsmask = PL01X_MSR_DCD;
1111 			sc->sc_ppsassert = -1;
1112 			sc->sc_ppsclear = 0;
1113 			break;
1114 
1115 		case PPS_CAPTUREBOTH:
1116 			sc->sc_ppsmask = PL01X_MSR_DCD;
1117 			sc->sc_ppsassert = PL01X_MSR_DCD;
1118 			sc->sc_ppsclear = 0;
1119 			break;
1120 
1121 		default:
1122 			error = EINVAL;
1123 			break;
1124 		}
1125 		mutex_spin_exit(&timecounter_lock);
1126 		break;
1127 	}
1128 
1129 	case PPS_IOC_GETCAP:
1130 		*(int*)data = ppscap;
1131 		break;
1132 
1133 	case PPS_IOC_FETCH: {
1134 		pps_info_t *pi;
1135 		pi = (pps_info_t *)data;
1136 		mutex_spin_enter(&timecounter_lock);
1137 		*pi = sc->ppsinfo;
1138 		mutex_spin_exit(&timecounter_lock);
1139 		break;
1140 	}
1141 
1142 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
1143 		/*
1144 		 * Some GPS clocks models use the falling rather than
1145 		 * rising edge as the on-the-second signal.
1146 		 * The old API has no way to specify PPS polarity.
1147 		 */
1148 		mutex_spin_enter(&timecounter_lock);
1149 		sc->sc_ppsmask = PL01X_MSR_DCD;
1150 #ifndef PPS_TRAILING_EDGE
1151 		sc->sc_ppsassert = PL01X_MSR_DCD;
1152 		sc->sc_ppsclear = -1;
1153 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1154 		    &sc->ppsinfo.assert_timestamp);
1155 #else
1156 		sc->sc_ppsassert = -1
1157 		sc->sc_ppsclear = 0;
1158 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1159 		    &sc->ppsinfo.clear_timestamp);
1160 #endif
1161 		mutex_spin_exit(&timecounter_lock);
1162 		break;
1163 
1164 	default:
1165 		error = EPASSTHROUGH;
1166 		break;
1167 	}
1168 
1169 	mutex_spin_exit(&sc->sc_lock);
1170 
1171 #ifdef PLCOM_DEBUG
1172 	if (plcom_debug)
1173 		plcomstatus(sc, "plcomioctl ");
1174 #endif
1175 
1176 	return error;
1177 }
1178 
1179 integrate void
1180 plcom_schedrx(struct plcom_softc *sc)
1181 {
1182 
1183 	sc->sc_rx_ready = 1;
1184 
1185 	/* Wake up the poller. */
1186 	softint_schedule(sc->sc_si);
1187 }
1188 
1189 void
1190 plcom_break(struct plcom_softc *sc, int onoff)
1191 {
1192 
1193 	if (onoff)
1194 		SET(sc->sc_lcr, PL01X_LCR_BRK);
1195 	else
1196 		CLR(sc->sc_lcr, PL01X_LCR_BRK);
1197 
1198 	if (!sc->sc_heldchange) {
1199 		if (sc->sc_tx_busy) {
1200 			sc->sc_heldtbc = sc->sc_tbc;
1201 			sc->sc_tbc = 0;
1202 			sc->sc_heldchange = 1;
1203 		} else
1204 			plcom_loadchannelregs(sc);
1205 	}
1206 }
1207 
1208 void
1209 plcom_modem(struct plcom_softc *sc, int onoff)
1210 {
1211 
1212 	if (sc->sc_mcr_dtr == 0)
1213 		return;
1214 
1215 	if (onoff)
1216 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1217 	else
1218 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1219 
1220 	if (!sc->sc_heldchange) {
1221 		if (sc->sc_tx_busy) {
1222 			sc->sc_heldtbc = sc->sc_tbc;
1223 			sc->sc_tbc = 0;
1224 			sc->sc_heldchange = 1;
1225 		} else
1226 			plcom_loadchannelregs(sc);
1227 	}
1228 }
1229 
1230 void
1231 tiocm_to_plcom(struct plcom_softc *sc, u_long how, int ttybits)
1232 {
1233 	u_char plcombits;
1234 
1235 	plcombits = 0;
1236 	if (ISSET(ttybits, TIOCM_DTR))
1237 		SET(plcombits, PL01X_MCR_DTR);
1238 	if (ISSET(ttybits, TIOCM_RTS))
1239 		SET(plcombits, PL01X_MCR_RTS);
1240 
1241 	switch (how) {
1242 	case TIOCMBIC:
1243 		CLR(sc->sc_mcr, plcombits);
1244 		break;
1245 
1246 	case TIOCMBIS:
1247 		SET(sc->sc_mcr, plcombits);
1248 		break;
1249 
1250 	case TIOCMSET:
1251 		CLR(sc->sc_mcr, PL01X_MCR_DTR | PL01X_MCR_RTS);
1252 		SET(sc->sc_mcr, plcombits);
1253 		break;
1254 	}
1255 
1256 	if (!sc->sc_heldchange) {
1257 		if (sc->sc_tx_busy) {
1258 			sc->sc_heldtbc = sc->sc_tbc;
1259 			sc->sc_tbc = 0;
1260 			sc->sc_heldchange = 1;
1261 		} else
1262 			plcom_loadchannelregs(sc);
1263 	}
1264 }
1265 
1266 int
1267 plcom_to_tiocm(struct plcom_softc *sc)
1268 {
1269 	u_char plcombits;
1270 	int ttybits = 0;
1271 
1272 	plcombits = sc->sc_mcr;
1273 	if (ISSET(plcombits, PL01X_MCR_DTR))
1274 		SET(ttybits, TIOCM_DTR);
1275 	if (ISSET(plcombits, PL01X_MCR_RTS))
1276 		SET(ttybits, TIOCM_RTS);
1277 
1278 	plcombits = sc->sc_msr;
1279 	if (ISSET(plcombits, PL01X_MSR_DCD))
1280 		SET(ttybits, TIOCM_CD);
1281 	if (ISSET(plcombits, PL01X_MSR_CTS))
1282 		SET(ttybits, TIOCM_CTS);
1283 	if (ISSET(plcombits, PL01X_MSR_DSR))
1284 		SET(ttybits, TIOCM_DSR);
1285 	if (ISSET(plcombits, PL011_MSR_RI))
1286 		SET(ttybits, TIOCM_RI);
1287 
1288 	if (sc->sc_cr != 0)
1289 		SET(ttybits, TIOCM_LE);
1290 
1291 	return ttybits;
1292 }
1293 
1294 static u_char
1295 cflag2lcr(tcflag_t cflag)
1296 {
1297 	u_char lcr = 0;
1298 
1299 	switch (ISSET(cflag, CSIZE)) {
1300 	case CS5:
1301 		SET(lcr, PL01X_LCR_5BITS);
1302 		break;
1303 	case CS6:
1304 		SET(lcr, PL01X_LCR_6BITS);
1305 		break;
1306 	case CS7:
1307 		SET(lcr, PL01X_LCR_7BITS);
1308 		break;
1309 	case CS8:
1310 		SET(lcr, PL01X_LCR_8BITS);
1311 		break;
1312 	}
1313 	if (ISSET(cflag, PARENB)) {
1314 		SET(lcr, PL01X_LCR_PEN);
1315 		if (!ISSET(cflag, PARODD))
1316 			SET(lcr, PL01X_LCR_EPS);
1317 	}
1318 	if (ISSET(cflag, CSTOPB))
1319 		SET(lcr, PL01X_LCR_STP2);
1320 
1321 	return lcr;
1322 }
1323 
1324 int
1325 plcomparam(struct tty *tp, struct termios *t)
1326 {
1327 	struct plcom_softc *sc =
1328 		device_lookup_private(&plcom_cd, PLCOMUNIT(tp->t_dev));
1329 	struct plcom_instance *pi = &sc->sc_pi;
1330 	int ospeed = -1;
1331 	u_char lcr;
1332 
1333 	if (PLCOM_ISALIVE(sc) == 0)
1334 		return EIO;
1335 
1336 	switch (pi->pi_type) {
1337 	case PLCOM_TYPE_PL010:
1338 		ospeed = pl010comspeed(t->c_ospeed, sc->sc_frequency);
1339 		break;
1340 	case PLCOM_TYPE_PL011:
1341 		ospeed = pl011comspeed(t->c_ospeed, sc->sc_frequency);
1342 		break;
1343 	}
1344 
1345 	/* Check requested parameters. */
1346 	if (ospeed < 0)
1347 		return EINVAL;
1348 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
1349 		return EINVAL;
1350 
1351 	/*
1352 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1353 	 * is always active.
1354 	 */
1355 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
1356 	    ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE)) {
1357 		SET(t->c_cflag, CLOCAL);
1358 		CLR(t->c_cflag, HUPCL);
1359 	}
1360 
1361 	/*
1362 	 * If there were no changes, don't do anything.  This avoids dropping
1363 	 * input and improves performance when all we did was frob things like
1364 	 * VMIN and VTIME.
1365 	 */
1366 	if (tp->t_ospeed == t->c_ospeed &&
1367 	    tp->t_cflag == t->c_cflag)
1368 		return 0;
1369 
1370 	lcr = ISSET(sc->sc_lcr, PL01X_LCR_BRK) | cflag2lcr(t->c_cflag);
1371 
1372 	mutex_spin_enter(&sc->sc_lock);
1373 
1374 	sc->sc_lcr = lcr;
1375 
1376 	/*
1377 	 * PL010 has a fixed-length FIFO trigger point.
1378 	 */
1379 	if (ISSET(sc->sc_hwflags, PLCOM_HW_FIFO))
1380 		sc->sc_fifo = 1;
1381 	else
1382 		sc->sc_fifo = 0;
1383 
1384 	if (sc->sc_fifo)
1385 		SET(sc->sc_lcr, PL01X_LCR_FEN);
1386 
1387 	/*
1388 	 * If we're not in a mode that assumes a connection is present, then
1389 	 * ignore carrier changes.
1390 	 */
1391 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
1392 		sc->sc_msr_dcd = 0;
1393 	else
1394 		sc->sc_msr_dcd = PL01X_MSR_DCD;
1395 	/*
1396 	 * Set the flow control pins depending on the current flow control
1397 	 * mode.
1398 	 */
1399 	if (ISSET(t->c_cflag, CRTSCTS)) {
1400 		sc->sc_mcr_dtr = PL01X_MCR_DTR;
1401 		sc->sc_mcr_rts = PL01X_MCR_RTS;
1402 		sc->sc_msr_cts = PL01X_MSR_CTS;
1403 	} else if (ISSET(t->c_cflag, MDMBUF)) {
1404 		/*
1405 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
1406 		 * carrier detection.
1407 		 */
1408 		sc->sc_mcr_dtr = 0;
1409 		sc->sc_mcr_rts = PL01X_MCR_DTR;
1410 		sc->sc_msr_cts = PL01X_MSR_DCD;
1411 	} else {
1412 		/*
1413 		 * If no flow control, then always set RTS.  This will make
1414 		 * the other side happy if it mistakenly thinks we're doing
1415 		 * RTS/CTS flow control.
1416 		 */
1417 		sc->sc_mcr_dtr = PL01X_MCR_DTR | PL01X_MCR_RTS;
1418 		sc->sc_mcr_rts = 0;
1419 		sc->sc_msr_cts = 0;
1420 		if (ISSET(sc->sc_mcr, PL01X_MCR_DTR))
1421 			SET(sc->sc_mcr, PL01X_MCR_RTS);
1422 		else
1423 			CLR(sc->sc_mcr, PL01X_MCR_RTS);
1424 	}
1425 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
1426 
1427 #if 0
1428 	if (ospeed == 0)
1429 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1430 	else
1431 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1432 #endif
1433 
1434 	switch (pi->pi_type) {
1435 	case PLCOM_TYPE_PL010:
1436 		sc->sc_ratel = ospeed & 0xff;
1437 		sc->sc_rateh = (ospeed >> 8) & 0xff;
1438 		break;
1439 	case PLCOM_TYPE_PL011:
1440 		sc->sc_ratel = ospeed & ((1 << 6) - 1);
1441 		sc->sc_rateh = ospeed >> 6;
1442 		break;
1443 	}
1444 
1445 	/* And copy to tty. */
1446 	tp->t_ispeed = t->c_ospeed;
1447 	tp->t_ospeed = t->c_ospeed;
1448 	tp->t_cflag = t->c_cflag;
1449 
1450 	if (!sc->sc_heldchange) {
1451 		if (sc->sc_tx_busy) {
1452 			sc->sc_heldtbc = sc->sc_tbc;
1453 			sc->sc_tbc = 0;
1454 			sc->sc_heldchange = 1;
1455 		} else
1456 			plcom_loadchannelregs(sc);
1457 	}
1458 
1459 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1460 		/* Disable the high water mark. */
1461 		sc->sc_r_hiwat = 0;
1462 		sc->sc_r_lowat = 0;
1463 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1464 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1465 			plcom_schedrx(sc);
1466 		}
1467 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1468 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1469 			plcom_hwiflow(sc);
1470 		}
1471 	} else {
1472 		sc->sc_r_hiwat = plcom_rbuf_hiwat;
1473 		sc->sc_r_lowat = plcom_rbuf_lowat;
1474 	}
1475 
1476 	mutex_spin_exit(&sc->sc_lock);
1477 
1478 	/*
1479 	 * Update the tty layer's idea of the carrier bit, in case we changed
1480 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1481 	 * explicit request.
1482 	 */
1483 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, PL01X_MSR_DCD));
1484 
1485 #ifdef PLCOM_DEBUG
1486 	if (plcom_debug)
1487 		plcomstatus(sc, "plcomparam ");
1488 #endif
1489 
1490 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1491 		if (sc->sc_tx_stopped) {
1492 			sc->sc_tx_stopped = 0;
1493 			plcomstart(tp);
1494 		}
1495 	}
1496 
1497 	return 0;
1498 }
1499 
1500 void
1501 plcom_iflush(struct plcom_softc *sc)
1502 {
1503 	struct plcom_instance *pi = &sc->sc_pi;
1504 #ifdef DIAGNOSTIC
1505 	int reg;
1506 #endif
1507 	int timo;
1508 
1509 #ifdef DIAGNOSTIC
1510 	reg = 0xffff;
1511 #endif
1512 	timo = 50000;
1513 	/* flush any pending I/O */
1514 	while (! ISSET(PREAD1(pi, PL01XCOM_FR), PL01X_FR_RXFE)
1515 	    && --timo)
1516 #ifdef DIAGNOSTIC
1517 		reg =
1518 #else
1519 		    (void)
1520 #endif
1521 		    PREAD1(pi, PL01XCOM_DR);
1522 #ifdef DIAGNOSTIC
1523 	if (!timo)
1524 		aprint_error_dev(sc->sc_dev, ": %s timeout %02x\n", __func__,
1525 		    reg);
1526 #endif
1527 }
1528 
1529 void
1530 plcom_loadchannelregs(struct plcom_softc *sc)
1531 {
1532 	struct plcom_instance *pi = &sc->sc_pi;
1533 
1534 	/* XXXXX necessary? */
1535 	plcom_iflush(sc);
1536 
1537 	switch (pi->pi_type) {
1538 	case PLCOM_TYPE_PL010:
1539 		PWRITE1(pi, PL010COM_CR, 0);
1540 		PWRITE1(pi, PL010COM_DLBL, sc->sc_ratel);
1541 		PWRITE1(pi, PL010COM_DLBH, sc->sc_rateh);
1542 		PWRITE1(pi, PL010COM_LCR, sc->sc_lcr);
1543 
1544 		/* XXX device_unit() abuse */
1545 		if (sc->sc_set_mcr)
1546 			sc->sc_set_mcr(sc->sc_set_mcr_arg,
1547 			    device_unit(sc->sc_dev),
1548 			    sc->sc_mcr_active = sc->sc_mcr);
1549 
1550 		PWRITE1(pi, PL010COM_CR, sc->sc_cr);
1551 		break;
1552 
1553 	case PLCOM_TYPE_PL011:
1554 		PWRITE4(pi, PL011COM_CR, 0);
1555 		PWRITE1(pi, PL011COM_FBRD, sc->sc_ratel);
1556 		PWRITE4(pi, PL011COM_IBRD, sc->sc_rateh);
1557 		PWRITE1(pi, PL011COM_LCRH, sc->sc_lcr);
1558 		sc->sc_mcr_active = sc->sc_mcr;
1559 		CLR(sc->sc_cr, PL011_MCR(PL01X_MCR_RTS | PL01X_MCR_DTR));
1560 		SET(sc->sc_cr, PL011_MCR(sc->sc_mcr_active));
1561 		PWRITE4(pi, PL011COM_CR, sc->sc_cr);
1562 		break;
1563 	}
1564 }
1565 
1566 int
1567 plcomhwiflow(struct tty *tp, int block)
1568 {
1569 	struct plcom_softc *sc =
1570 		device_lookup_private(&plcom_cd, PLCOMUNIT(tp->t_dev));
1571 
1572 	if (PLCOM_ISALIVE(sc) == 0)
1573 		return 0;
1574 
1575 	if (sc->sc_mcr_rts == 0)
1576 		return 0;
1577 
1578 	mutex_spin_enter(&sc->sc_lock);
1579 
1580 	if (block) {
1581 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1582 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
1583 			plcom_hwiflow(sc);
1584 		}
1585 	} else {
1586 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1587 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1588 			plcom_schedrx(sc);
1589 		}
1590 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1591 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
1592 			plcom_hwiflow(sc);
1593 		}
1594 	}
1595 
1596 	mutex_spin_exit(&sc->sc_lock);
1597 	return 1;
1598 }
1599 
1600 /*
1601  * (un)block input via hw flowcontrol
1602  */
1603 void
1604 plcom_hwiflow(struct plcom_softc *sc)
1605 {
1606 	struct plcom_instance *pi = &sc->sc_pi;
1607 
1608 	if (sc->sc_mcr_rts == 0)
1609 		return;
1610 
1611 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
1612 		CLR(sc->sc_mcr, sc->sc_mcr_rts);
1613 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
1614 	} else {
1615 		SET(sc->sc_mcr, sc->sc_mcr_rts);
1616 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
1617 	}
1618 	switch (pi->pi_type) {
1619 	case PLCOM_TYPE_PL010:
1620 		if (sc->sc_set_mcr)
1621 			/* XXX device_unit() abuse */
1622 			sc->sc_set_mcr(sc->sc_set_mcr_arg,
1623 			     device_unit(sc->sc_dev), sc->sc_mcr_active);
1624 		break;
1625 	case PLCOM_TYPE_PL011:
1626 		CLR(sc->sc_cr, PL011_MCR(PL01X_MCR_RTS | PL01X_MCR_DTR));
1627 		SET(sc->sc_cr, PL011_MCR(sc->sc_mcr_active));
1628 		PWRITE4(pi, PL011COM_CR, sc->sc_cr);
1629 		break;
1630 	}
1631 }
1632 
1633 
1634 void
1635 plcomstart(struct tty *tp)
1636 {
1637 	struct plcom_softc *sc =
1638 		device_lookup_private(&plcom_cd, PLCOMUNIT(tp->t_dev));
1639 	struct plcom_instance *pi = &sc->sc_pi;
1640 	int s;
1641 
1642 	if (PLCOM_ISALIVE(sc) == 0)
1643 		return;
1644 
1645 	s = spltty();
1646 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1647 		goto out;
1648 	if (sc->sc_tx_stopped)
1649 		goto out;
1650 
1651 	if (!ttypull(tp))
1652 		goto out;
1653 
1654 	/* Grab the first contiguous region of buffer space. */
1655 	{
1656 		u_char *tba;
1657 		int tbc;
1658 
1659 		tba = tp->t_outq.c_cf;
1660 		tbc = ndqb(&tp->t_outq, 0);
1661 
1662 		mutex_spin_enter(&sc->sc_lock);
1663 
1664 		sc->sc_tba = tba;
1665 		sc->sc_tbc = tbc;
1666 	}
1667 
1668 	SET(tp->t_state, TS_BUSY);
1669 	sc->sc_tx_busy = 1;
1670 
1671 	/* Enable transmit completion interrupts if necessary. */
1672 	switch (pi->pi_type) {
1673 	case PLCOM_TYPE_PL010:
1674 		if (!ISSET(sc->sc_cr, PL010_CR_TIE)) {
1675 			SET(sc->sc_cr, PL010_CR_TIE);
1676 			PWRITE1(pi, PL010COM_CR, sc->sc_cr);
1677 		}
1678 		break;
1679 	case PLCOM_TYPE_PL011:
1680 		if (!ISSET(sc->sc_imsc, PL011_INT_TX)) {
1681 			SET(sc->sc_imsc, PL011_INT_TX);
1682 			PWRITE4(pi, PL011COM_IMSC, sc->sc_imsc);
1683 		}
1684 		break;
1685 	}
1686 
1687 	/* Output the first chunk of the contiguous buffer. */
1688 	{
1689 		int n;
1690 
1691 		n = sc->sc_tbc;
1692 		if (n > sc->sc_fifolen)
1693 			n = sc->sc_fifolen;
1694 		PWRITEM1(pi, PL01XCOM_DR, sc->sc_tba, n);
1695 		sc->sc_tbc -= n;
1696 		sc->sc_tba += n;
1697 	}
1698 	mutex_spin_exit(&sc->sc_lock);
1699 out:
1700 	splx(s);
1701 	return;
1702 }
1703 
1704 /*
1705  * Stop output on a line.
1706  */
1707 void
1708 plcomstop(struct tty *tp, int flag)
1709 {
1710 	struct plcom_softc *sc =
1711 		device_lookup_private(&plcom_cd, PLCOMUNIT(tp->t_dev));
1712 
1713 	mutex_spin_enter(&sc->sc_lock);
1714 	if (ISSET(tp->t_state, TS_BUSY)) {
1715 		/* Stop transmitting at the next chunk. */
1716 		sc->sc_tbc = 0;
1717 		sc->sc_heldtbc = 0;
1718 		if (!ISSET(tp->t_state, TS_TTSTOP))
1719 			SET(tp->t_state, TS_FLUSH);
1720 	}
1721 	mutex_spin_exit(&sc->sc_lock);
1722 }
1723 
1724 void
1725 plcomdiag(void *arg)
1726 {
1727 	struct plcom_softc *sc = arg;
1728 	int overflows, floods;
1729 
1730 	mutex_spin_enter(&sc->sc_lock);
1731 	overflows = sc->sc_overflows;
1732 	sc->sc_overflows = 0;
1733 	floods = sc->sc_floods;
1734 	sc->sc_floods = 0;
1735 	sc->sc_errors = 0;
1736 	mutex_spin_exit(&sc->sc_lock);
1737 
1738 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
1739 	    device_xname(sc->sc_dev),
1740 	    overflows, overflows == 1 ? "" : "s",
1741 	    floods, floods == 1 ? "" : "s");
1742 }
1743 
1744 integrate void
1745 plcom_rxsoft(struct plcom_softc *sc, struct tty *tp)
1746 {
1747 	int (*rint) (int, struct tty *) = tp->t_linesw->l_rint;
1748 	struct plcom_instance *pi = &sc->sc_pi;
1749 	u_char *get, *end;
1750 	u_int cc, scc;
1751 	u_char rsr;
1752 	int code;
1753 
1754 	end = sc->sc_ebuf;
1755 	get = sc->sc_rbget;
1756 	scc = cc = plcom_rbuf_size - sc->sc_rbavail;
1757 
1758 	if (cc == plcom_rbuf_size) {
1759 		sc->sc_floods++;
1760 		if (sc->sc_errors++ == 0)
1761 			callout_reset(&sc->sc_diag_callout, 60 * hz,
1762 			    plcomdiag, sc);
1763 	}
1764 
1765 	while (cc) {
1766 		code = get[0];
1767 		rsr = get[1];
1768 		if (ISSET(rsr, PL01X_RSR_ERROR)) {
1769 			if (ISSET(rsr, PL01X_RSR_OE)) {
1770 				sc->sc_overflows++;
1771 				if (sc->sc_errors++ == 0)
1772 					callout_reset(&sc->sc_diag_callout,
1773 					    60 * hz, plcomdiag, sc);
1774 			}
1775 			if (ISSET(rsr, PL01X_RSR_BE | PL01X_RSR_FE))
1776 				SET(code, TTY_FE);
1777 			if (ISSET(rsr, PL01X_RSR_PE))
1778 				SET(code, TTY_PE);
1779 		}
1780 		if ((*rint)(code, tp) == -1) {
1781 			/*
1782 			 * The line discipline's buffer is out of space.
1783 			 */
1784 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1785 				/*
1786 				 * We're either not using flow control, or the
1787 				 * line discipline didn't tell us to block for
1788 				 * some reason.  Either way, we have no way to
1789 				 * know when there's more space available, so
1790 				 * just drop the rest of the data.
1791 				 */
1792 				get += cc << 1;
1793 				if (get >= end)
1794 					get -= plcom_rbuf_size << 1;
1795 				cc = 0;
1796 			} else {
1797 				/*
1798 				 * Don't schedule any more receive processing
1799 				 * until the line discipline tells us there's
1800 				 * space available (through plcomhwiflow()).
1801 				 * Leave the rest of the data in the input
1802 				 * buffer.
1803 				 */
1804 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1805 			}
1806 			break;
1807 		}
1808 		get += 2;
1809 		if (get >= end)
1810 			get = sc->sc_rbuf;
1811 		cc--;
1812 	}
1813 
1814 	if (cc != scc) {
1815 		sc->sc_rbget = get;
1816 		mutex_spin_enter(&sc->sc_lock);
1817 
1818 		cc = sc->sc_rbavail += scc - cc;
1819 		/* Buffers should be ok again, release possible block. */
1820 		if (cc >= sc->sc_r_lowat) {
1821 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1822 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1823 				switch (pi->pi_type) {
1824 				case PLCOM_TYPE_PL010:
1825 					SET(sc->sc_cr,
1826 					    PL010_CR_RIE | PL010_CR_RTIE);
1827 					PWRITE1(pi, PL010COM_CR, sc->sc_cr);
1828 					break;
1829 				case PLCOM_TYPE_PL011:
1830 					SET(sc->sc_imsc,
1831 					    PL011_INT_RX | PL011_INT_RT);
1832 					PWRITE4(pi, PL011COM_IMSC, sc->sc_imsc);
1833 					break;
1834 				}
1835 			}
1836 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
1837 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1838 				plcom_hwiflow(sc);
1839 			}
1840 		}
1841 		mutex_spin_exit(&sc->sc_lock);
1842 	}
1843 }
1844 
1845 integrate void
1846 plcom_txsoft(struct plcom_softc *sc, struct tty *tp)
1847 {
1848 
1849 	CLR(tp->t_state, TS_BUSY);
1850 	if (ISSET(tp->t_state, TS_FLUSH))
1851 		CLR(tp->t_state, TS_FLUSH);
1852 	else
1853 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
1854 	(*tp->t_linesw->l_start)(tp);
1855 }
1856 
1857 integrate void
1858 plcom_stsoft(struct plcom_softc *sc, struct tty *tp)
1859 {
1860 	u_char msr, delta;
1861 
1862 	mutex_spin_enter(&sc->sc_lock);
1863 	msr = sc->sc_msr;
1864 	delta = sc->sc_msr_delta;
1865 	sc->sc_msr_delta = 0;
1866 	mutex_spin_exit(&sc->sc_lock);
1867 
1868 	if (ISSET(delta, sc->sc_msr_dcd)) {
1869 		/*
1870 		 * Inform the tty layer that carrier detect changed.
1871 		 */
1872 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, PL01X_MSR_DCD));
1873 	}
1874 
1875 	if (ISSET(delta, sc->sc_msr_cts)) {
1876 		/* Block or unblock output according to flow control. */
1877 		if (ISSET(msr, sc->sc_msr_cts)) {
1878 			sc->sc_tx_stopped = 0;
1879 			(*tp->t_linesw->l_start)(tp);
1880 		} else {
1881 			sc->sc_tx_stopped = 1;
1882 		}
1883 	}
1884 
1885 #ifdef PLCOM_DEBUG
1886 	if (plcom_debug)
1887 		plcomstatus(sc, "plcom_stsoft");
1888 #endif
1889 }
1890 
1891 void
1892 plcomsoft(void *arg)
1893 {
1894 	struct plcom_softc *sc = arg;
1895 	struct tty *tp;
1896 
1897 	if (PLCOM_ISALIVE(sc) == 0)
1898 		return;
1899 
1900 	tp = sc->sc_tty;
1901 
1902 	if (sc->sc_rx_ready) {
1903 		sc->sc_rx_ready = 0;
1904 		plcom_rxsoft(sc, tp);
1905 	}
1906 
1907 	if (sc->sc_st_check) {
1908 		sc->sc_st_check = 0;
1909 		plcom_stsoft(sc, tp);
1910 	}
1911 
1912 	if (sc->sc_tx_done) {
1913 		sc->sc_tx_done = 0;
1914 		plcom_txsoft(sc, tp);
1915 	}
1916 }
1917 
1918 bool
1919 plcom_intstatus(struct plcom_instance *pi, u_int *istatus)
1920 {
1921 	bool ret = false;
1922 	u_int stat = 0;
1923 
1924 	switch (pi->pi_type) {
1925 	case PLCOM_TYPE_PL010:
1926 		stat = PREAD1(pi, PL010COM_IIR);
1927 		ret = ISSET(stat, PL010_IIR_IMASK);
1928 		break;
1929 	case PLCOM_TYPE_PL011:
1930 		stat = PREAD4(pi, PL011COM_MIS);
1931 		ret = ISSET(stat, PL011_INT_ALLMASK);
1932 		break;
1933 	}
1934 	*istatus = stat;
1935 
1936 	return ret;
1937 }
1938 
1939 int
1940 plcomintr(void *arg)
1941 {
1942 	struct plcom_softc *sc = arg;
1943 	struct plcom_instance *pi = &sc->sc_pi;
1944 	u_char *put, *end;
1945 	u_int cc;
1946 	u_int istatus = 0;
1947 	u_char rsr;
1948 	bool intr = false;
1949 
1950 	PLCOM_BARRIER(pi, BR | BW);
1951 
1952 	if (PLCOM_ISALIVE(sc) == 0)
1953 		return 0;
1954 
1955 	mutex_spin_enter(&sc->sc_lock);
1956 	intr = plcom_intstatus(pi, &istatus);
1957 	if (!intr) {
1958 		mutex_spin_exit(&sc->sc_lock);
1959 		return 0;
1960 	}
1961 
1962 	end = sc->sc_ebuf;
1963 	put = sc->sc_rbput;
1964 	cc = sc->sc_rbavail;
1965 
1966 	do {
1967 		u_int msr = 0, delta, fr;
1968 		bool rxintr = false, txintr = false, msintr;
1969 
1970 		/* don't need RI here*/
1971 		fr = PREAD1(pi, PL01XCOM_FR);
1972 
1973 		if (!ISSET(fr, PL01X_FR_RXFE) &&
1974 		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1975 			while (cc > 0) {
1976 				int cn_trapped = 0;
1977 				put[0] = PREAD1(pi, PL01XCOM_DR);
1978 				rsr = PREAD1(pi, PL01XCOM_RSR);
1979 				/* Clear any error status.  */
1980 				if (ISSET(rsr, PL01X_RSR_ERROR))
1981 					PWRITE1(pi, PL01XCOM_ECR, 0);
1982 				if (ISSET(rsr, PL01X_RSR_BE)) {
1983 					cn_trapped = 0;
1984 					cn_check_magic(sc->sc_tty->t_dev,
1985 					    CNC_BREAK, plcom_cnm_state);
1986 					if (cn_trapped)
1987 						continue;
1988 #if defined(KGDB)
1989 					if (ISSET(sc->sc_hwflags,
1990 					    PLCOM_HW_KGDB)) {
1991 						kgdb_connect(1);
1992 						continue;
1993 					}
1994 #endif
1995 				}
1996 
1997 				put[1] = rsr;
1998 				cn_trapped = 0;
1999 				cn_check_magic(sc->sc_tty->t_dev, put[0],
2000 				    plcom_cnm_state);
2001 				if (cn_trapped) {
2002 					fr = PREAD1(pi, PL01XCOM_FR);
2003 					if (ISSET(fr, PL01X_FR_RXFE))
2004 						break;
2005 
2006 					continue;
2007 				}
2008 				put += 2;
2009 				if (put >= end)
2010 					put = sc->sc_rbuf;
2011 				cc--;
2012 
2013 				/* don't need RI here*/
2014 				fr = PREAD1(pi, PL01XCOM_FR);
2015 				if (ISSET(fr, PL01X_FR_RXFE))
2016 					break;
2017 			}
2018 
2019 			/*
2020 			 * Current string of incoming characters ended because
2021 			 * no more data was available or we ran out of space.
2022 			 * Schedule a receive event if any data was received.
2023 			 * If we're out of space, turn off receive interrupts.
2024 			 */
2025 			sc->sc_rbput = put;
2026 			sc->sc_rbavail = cc;
2027 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
2028 				sc->sc_rx_ready = 1;
2029 
2030 			/*
2031 			 * See if we are in danger of overflowing a buffer. If
2032 			 * so, use hardware flow control to ease the pressure.
2033 			 */
2034 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
2035 			    cc < sc->sc_r_hiwat) {
2036 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
2037 				plcom_hwiflow(sc);
2038 			}
2039 
2040 			/*
2041 			 * If we're out of space, disable receive interrupts
2042 			 * until the queue has drained a bit.
2043 			 */
2044 			if (!cc) {
2045 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
2046 				switch (pi->pi_type) {
2047 				case PLCOM_TYPE_PL010:
2048 					CLR(sc->sc_cr,
2049 					    PL010_CR_RIE | PL010_CR_RTIE);
2050 					PWRITE1(pi, PL010COM_CR, sc->sc_cr);
2051 					break;
2052 				case PLCOM_TYPE_PL011:
2053 					CLR(sc->sc_imsc,
2054 					    PL011_INT_RT | PL011_INT_RX);
2055 					PWRITE4(pi, PL011COM_IMSC, sc->sc_imsc);
2056 					break;
2057 				}
2058 			}
2059 		} else {
2060 			switch (pi->pi_type) {
2061 			case PLCOM_TYPE_PL010:
2062 				rxintr = ISSET(istatus, PL010_IIR_RIS);
2063 				if (rxintr) {
2064 					PWRITE1(pi, PL010COM_CR, 0);
2065 					delay(10);
2066 					PWRITE1(pi, PL010COM_CR, sc->sc_cr);
2067 					continue;
2068 				}
2069 				break;
2070 			case PLCOM_TYPE_PL011:
2071 				rxintr = ISSET(istatus, PL011_INT_RX);
2072 				if (rxintr) {
2073 					PWRITE4(pi, PL011COM_CR, 0);
2074 					delay(10);
2075 					PWRITE4(pi, PL011COM_CR, sc->sc_cr);
2076 					continue;
2077 				}
2078 				break;
2079 			}
2080 		}
2081 
2082 		switch (pi->pi_type) {
2083 		case PLCOM_TYPE_PL010:
2084 			msr = PREAD1(pi, PL01XCOM_FR);
2085 			break;
2086 		case PLCOM_TYPE_PL011:
2087 			msr = PREAD4(pi, PL01XCOM_FR);
2088 			break;
2089 		}
2090 		delta = msr ^ sc->sc_msr;
2091 		sc->sc_msr = msr;
2092 
2093 		/* Clear any pending modem status interrupt.  */
2094 		switch (pi->pi_type) {
2095 		case PLCOM_TYPE_PL010:
2096 			msintr = ISSET(istatus, PL010_IIR_MIS);
2097 			if (msintr) {
2098 				PWRITE1(pi, PL010COM_ICR, 0);
2099 			}
2100 			break;
2101 		case PLCOM_TYPE_PL011:
2102 			msintr = ISSET(istatus, PL011_INT_MSMASK);
2103 			if (msintr) {
2104 				PWRITE4(pi, PL011COM_ICR, PL011_INT_MSMASK);
2105 			}
2106 			break;
2107 		}
2108 		/*
2109 		 * Pulse-per-second (PSS) signals on edge of DCD?
2110 		 * Process these even if line discipline is ignoring DCD.
2111 		 */
2112 		if (delta & sc->sc_ppsmask) {
2113 			struct timeval tv;
2114 			mutex_spin_enter(&timecounter_lock);
2115 		    	if ((msr & sc->sc_ppsmask) == sc->sc_ppsassert) {
2116 				/* XXX nanotime() */
2117 				microtime(&tv);
2118 				TIMEVAL_TO_TIMESPEC(&tv,
2119 				    &sc->ppsinfo.assert_timestamp);
2120 				if (sc->ppsparam.mode & PPS_OFFSETASSERT) {
2121 					timespecadd(&sc->ppsinfo.assert_timestamp,
2122 					    &sc->ppsparam.assert_offset,
2123 						    &sc->ppsinfo.assert_timestamp);
2124 				}
2125 
2126 #ifdef PPS_SYNC
2127 				if (sc->ppsparam.mode & PPS_HARDPPSONASSERT)
2128 					hardpps(&tv, tv.tv_usec);
2129 #endif
2130 				sc->ppsinfo.assert_sequence++;
2131 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
2132 
2133 			} else if ((msr & sc->sc_ppsmask) == sc->sc_ppsclear) {
2134 				/* XXX nanotime() */
2135 				microtime(&tv);
2136 				TIMEVAL_TO_TIMESPEC(&tv,
2137 				    &sc->ppsinfo.clear_timestamp);
2138 				if (sc->ppsparam.mode & PPS_OFFSETCLEAR) {
2139 					timespecadd(&sc->ppsinfo.clear_timestamp,
2140 					    &sc->ppsparam.clear_offset,
2141 					    &sc->ppsinfo.clear_timestamp);
2142 				}
2143 
2144 #ifdef PPS_SYNC
2145 				if (sc->ppsparam.mode & PPS_HARDPPSONCLEAR)
2146 					hardpps(&tv, tv.tv_usec);
2147 #endif
2148 				sc->ppsinfo.clear_sequence++;
2149 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
2150 			}
2151 			mutex_spin_exit(&timecounter_lock);
2152 		}
2153 
2154 		/*
2155 		 * Process normal status changes
2156 		 */
2157 		if (ISSET(delta, sc->sc_msr_mask)) {
2158 			SET(sc->sc_msr_delta, delta);
2159 
2160 			/*
2161 			 * Stop output immediately if we lose the output
2162 			 * flow control signal or carrier detect.
2163 			 */
2164 			if (ISSET(~msr, sc->sc_msr_mask)) {
2165 				sc->sc_tbc = 0;
2166 				sc->sc_heldtbc = 0;
2167 #ifdef PLCOM_DEBUG
2168 				if (plcom_debug)
2169 					plcomstatus(sc, "plcomintr  ");
2170 #endif
2171 			}
2172 
2173 			sc->sc_st_check = 1;
2174 		}
2175 
2176 		/*
2177 		 * Done handling any receive interrupts. See if data
2178 		 * can be transmitted as well. Schedule tx done
2179 		 * event if no data left and tty was marked busy.
2180 		 */
2181 
2182 		switch (pi->pi_type) {
2183 		case PLCOM_TYPE_PL010:
2184 			txintr = ISSET(istatus, PL010_IIR_TIS);
2185 			break;
2186 		case PLCOM_TYPE_PL011:
2187 			txintr = ISSET(istatus, PL011_INT_TX);
2188 			break;
2189 		}
2190 		if (txintr) {
2191 			/*
2192 			 * If we've delayed a parameter change, do it
2193 			 * now, and restart * output.
2194 			 */
2195 // PWRITE4(pi, PL011COM_ICR, PL011_INT_TX);
2196 			if (sc->sc_heldchange) {
2197 				plcom_loadchannelregs(sc);
2198 				sc->sc_heldchange = 0;
2199 				sc->sc_tbc = sc->sc_heldtbc;
2200 				sc->sc_heldtbc = 0;
2201 			}
2202 
2203 			/*
2204 			 * Output the next chunk of the contiguous
2205 			 * buffer, if any.
2206 			 */
2207 			if (sc->sc_tbc > 0) {
2208 				int n;
2209 
2210 				n = sc->sc_tbc;
2211 				if (n > sc->sc_fifolen)
2212 					n = sc->sc_fifolen;
2213 				PWRITEM1(pi, PL01XCOM_DR, sc->sc_tba, n);
2214 				sc->sc_tbc -= n;
2215 				sc->sc_tba += n;
2216 			} else {
2217 				/*
2218 				 * Disable transmit completion
2219 				 * interrupts if necessary.
2220 				 */
2221 				switch (pi->pi_type) {
2222 				case PLCOM_TYPE_PL010:
2223 					if (ISSET(sc->sc_cr, PL010_CR_TIE)) {
2224 						CLR(sc->sc_cr, PL010_CR_TIE);
2225 						PWRITE1(pi, PL010COM_CR,
2226 						    sc->sc_cr);
2227 					}
2228 					break;
2229 				case PLCOM_TYPE_PL011:
2230 					if (ISSET(sc->sc_imsc, PL011_INT_TX)) {
2231 						CLR(sc->sc_imsc, PL011_INT_TX);
2232 						PWRITE4(pi, PL011COM_IMSC,
2233 						    sc->sc_imsc);
2234 					}
2235 					break;
2236 				}
2237 				if (sc->sc_tx_busy) {
2238 					sc->sc_tx_busy = 0;
2239 					sc->sc_tx_done = 1;
2240 				}
2241 			}
2242 		}
2243 
2244 	} while (plcom_intstatus(pi, &istatus));
2245 
2246 	mutex_spin_exit(&sc->sc_lock);
2247 
2248 	/* Wake up the poller. */
2249 	softint_schedule(sc->sc_si);
2250 
2251 #ifdef RND_COM
2252 	rnd_add_uint32(&sc->rnd_source, istatus | rsr);
2253 #endif
2254 
2255 	PLCOM_BARRIER(pi, BR | BW);
2256 
2257 	return 1;
2258 }
2259 
2260 /*
2261  * The following functions are polled getc and putc routines, shared
2262  * by the console and kgdb glue.
2263  *
2264  * The read-ahead code is so that you can detect pending in-band
2265  * cn_magic in polled mode while doing output rather than having to
2266  * wait until the kernel decides it needs input.
2267  */
2268 
2269 #define MAX_READAHEAD	20
2270 static int plcom_readahead[MAX_READAHEAD];
2271 static int plcom_readaheadcount = 0;
2272 
2273 int
2274 plcom_common_getc(dev_t dev, struct plcom_instance *pi)
2275 {
2276 	int s = splserial();
2277 	u_char stat, c;
2278 
2279 	/* got a character from reading things earlier */
2280 	if (plcom_readaheadcount > 0) {
2281 		int i;
2282 
2283 		c = plcom_readahead[0];
2284 		for (i = 1; i < plcom_readaheadcount; i++) {
2285 			plcom_readahead[i-1] = plcom_readahead[i];
2286 		}
2287 		plcom_readaheadcount--;
2288 		splx(s);
2289 		return c;
2290 	}
2291 
2292 	/* block until a character becomes available */
2293 	while (ISSET(stat = PREAD1(pi, PL01XCOM_FR), PL01X_FR_RXFE))
2294 		;
2295 
2296 	c = PREAD1(pi, PL01XCOM_DR);
2297 	{
2298 		int cn_trapped __unused = 0;
2299 #ifdef DDB
2300 		extern int db_active;
2301 		if (!db_active)
2302 #endif
2303 			cn_check_magic(dev, c, plcom_cnm_state);
2304 	}
2305 	splx(s);
2306 	return c;
2307 }
2308 
2309 void
2310 plcom_common_putc(dev_t dev, struct plcom_instance *pi, int c)
2311 {
2312 	int s = splserial();
2313 	int timo;
2314 
2315 	int cin, stat;
2316 	if (plcom_readaheadcount < MAX_READAHEAD
2317 	     && !ISSET(stat = PREAD1(pi, PL01XCOM_FR), PL01X_FR_RXFE)) {
2318 		int cn_trapped __unused = 0;
2319 		cin = PREAD1(pi, PL01XCOM_DR);
2320 		cn_check_magic(dev, cin, plcom_cnm_state);
2321 		plcom_readahead[plcom_readaheadcount++] = cin;
2322 	}
2323 
2324 	/* wait for any pending transmission to finish */
2325 	timo = 150000;
2326 	while (ISSET(PREAD1(pi, PL01XCOM_FR), PL01X_FR_TXFF) && --timo)
2327 		continue;
2328 
2329 	PWRITE1(pi, PL01XCOM_DR, c);
2330 	PLCOM_BARRIER(pi, BR | BW);
2331 
2332 	/* wait for this transmission to complete */
2333 	timo = 1500000;
2334 	while (!ISSET(PREAD1(pi, PL01XCOM_FR), PL01X_FR_TXFE) && --timo)
2335 		continue;
2336 
2337 	splx(s);
2338 }
2339 
2340 /*
2341  * Initialize UART for use as console or KGDB line.
2342  */
2343 int
2344 plcominit(struct plcom_instance *pi, int rate, int frequency, tcflag_t cflag)
2345 {
2346 	u_char lcr;
2347 
2348 	switch (pi->pi_type) {
2349 	case PLCOM_TYPE_PL010:
2350 		if (pi->pi_size == 0)
2351 			pi->pi_size = PL010COM_UART_SIZE;
2352 		break;
2353 	case PLCOM_TYPE_PL011:
2354 		if (pi->pi_size == 0)
2355 			pi->pi_size = PL011COM_UART_SIZE;
2356 		break;
2357 	default:
2358 		panic("Unknown plcom type");
2359 	}
2360 
2361 	if (bus_space_map(pi->pi_iot, pi->pi_iobase, pi->pi_size, 0,
2362 	    &pi->pi_ioh))
2363 		return ENOMEM; /* ??? */
2364 
2365 	lcr = cflag2lcr(cflag) | PL01X_LCR_FEN;
2366 	switch (pi->pi_type) {
2367 	case PLCOM_TYPE_PL010:
2368 		PWRITE1(pi, PL010COM_CR, 0);
2369 
2370 		rate = pl010comspeed(rate, frequency);
2371 		PWRITE1(pi, PL010COM_DLBL, (rate & 0xff));
2372 		PWRITE1(pi, PL010COM_DLBH, ((rate >> 8) & 0xff));
2373 		PWRITE1(pi, PL010COM_LCR, lcr);
2374 		PWRITE1(pi, PL010COM_CR, PL01X_CR_UARTEN);
2375 		break;
2376 	case PLCOM_TYPE_PL011:
2377 		PWRITE4(pi, PL011COM_CR, 0);
2378 
2379 		rate = pl011comspeed(rate, frequency);
2380 		PWRITE1(pi, PL011COM_FBRD, rate & ((1 << 6) - 1));
2381 		PWRITE4(pi, PL011COM_IBRD, rate >> 6);
2382 		PWRITE1(pi, PL011COM_LCRH, lcr);
2383 		PWRITE4(pi, PL011COM_CR,
2384 		    PL01X_CR_UARTEN | PL011_CR_RXE | PL011_CR_TXE);
2385 		break;
2386 	}
2387 
2388 #if 0
2389 	/* Ought to do something like this, but we have no sc to
2390 	   dereference. */
2391 	/* XXX device_unit() abuse */
2392 	sc->sc_set_mcr(sc->sc_set_mcr_arg, device_unit(sc->sc_dev),
2393 	    PL01X_MCR_DTR | PL01X_MCR_RTS);
2394 #endif
2395 
2396 	return 0;
2397 }
2398 
2399 /*
2400  * Following are all routines needed for PLCOM to act as console
2401  */
2402 struct consdev plcomcons = {
2403 	NULL, NULL, plcomcngetc, plcomcnputc, plcomcnpollc, NULL,
2404 	NULL, NULL, NODEV, CN_NORMAL
2405 };
2406 
2407 int
2408 plcomcnattach(struct plcom_instance *pi, int rate, int frequency,
2409     tcflag_t cflag, int unit)
2410 {
2411 	int res;
2412 
2413 	plcomcons_info = *pi;
2414 
2415 	res = plcominit(&plcomcons_info, rate, frequency, cflag);
2416 	if (res)
2417 		return res;
2418 
2419 	cn_tab = &plcomcons;
2420 	cn_init_magic(&plcom_cnm_state);
2421 	cn_set_magic("\047\001"); /* default magic is BREAK */
2422 
2423 	plcomconsunit = unit;
2424 	plcomconsrate = rate;
2425 	plcomconscflag = cflag;
2426 
2427 	return 0;
2428 }
2429 
2430 void
2431 plcomcndetach(void)
2432 {
2433 
2434 	bus_space_unmap(plcomcons_info.pi_iot, plcomcons_info.pi_ioh,
2435 	    plcomcons_info.pi_size);
2436 	plcomcons_info.pi_iot = NULL;
2437 
2438 	cn_tab = NULL;
2439 }
2440 
2441 int
2442 plcomcngetc(dev_t dev)
2443 {
2444 	return plcom_common_getc(dev, &plcomcons_info);
2445 }
2446 
2447 /*
2448  * Console kernel output character routine.
2449  */
2450 void
2451 plcomcnputc(dev_t dev, int c)
2452 {
2453 	plcom_common_putc(dev, &plcomcons_info, c);
2454 }
2455 
2456 void
2457 plcomcnpollc(dev_t dev, int on)
2458 {
2459 
2460 	plcom_readaheadcount = 0;
2461 }
2462 
2463 #ifdef KGDB
2464 int
2465 plcom_kgdb_attach(struct plcom_instance *pi, int rate, int frequency,
2466     tcflag_t cflag, int unit)
2467 {
2468 	int res;
2469 
2470 	if (pi->pi_iot == plcomcons_info.pi_iot &&
2471 	    pi->pi_iobase == plcomcons_info.pi_iobase)
2472 		return EBUSY; /* cannot share with console */
2473 
2474 	res = plcominit(pi, rate, frequency, cflag);
2475 	if (res)
2476 		return res;
2477 
2478 	kgdb_attach(plcom_kgdb_getc, plcom_kgdb_putc, NULL);
2479 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
2480 
2481 	plcomkgdb_info.pi_iot = pi->pi_iot;
2482 	plcomkgdb_info.pi_ioh = pi->pi_ioh;
2483 	plcomkgdb_info.pi_iobase = pi->pi_iobase;
2484 
2485 	return 0;
2486 }
2487 
2488 /* ARGSUSED */
2489 int
2490 plcom_kgdb_getc(void *arg)
2491 {
2492 	return plcom_common_getc(NODEV, &plcomkgdb_info);
2493 }
2494 
2495 /* ARGSUSED */
2496 void
2497 plcom_kgdb_putc(void *arg, int c)
2498 {
2499 	plcom_common_putc(NODEV, &plcomkgdb_info, c);
2500 }
2501 #endif /* KGDB */
2502 
2503 /* helper function to identify the plcom ports used by
2504  console or KGDB (and not yet autoconf attached) */
2505 int
2506 plcom_is_console(bus_space_tag_t iot, bus_addr_t iobase,
2507     bus_space_handle_t *ioh)
2508 {
2509 	bus_space_handle_t help;
2510 
2511 	if (!plcomconsattached &&
2512 	    bus_space_is_equal(iot, plcomcons_info.pi_iot) &&
2513 	    iobase == plcomcons_info.pi_iobase)
2514 		help = plcomcons_info.pi_ioh;
2515 #ifdef KGDB
2516 	else if (!plcom_kgdb_attached &&
2517 	    bus_space_is_equal(iot, plcomkgdb_info.pi_iot) &&
2518 	    iobase == plcomkgdb_info.pi_iobase)
2519 		help = plcomkgdb_info.pi_ioh;
2520 #endif
2521 	else
2522 		return 0;
2523 
2524 	if (ioh)
2525 		*ioh = help;
2526 	return 1;
2527 }
2528